A number of factors can cause the scalp to itch. MayoClinic.com maintains that dry skin is mostly harmless, but the itching can be embarrassing and irritating. An itching scalp can often be controlled by mundane methods. If serious, however,, a diagnosis will take into consideration the history and type of scaling, how long it has persisted, the severity, and to what extent the problem has spread.
Environmental Causes
MayoClinic.com states that many times the factors involving an itchy scalp are environmental ones that can be controlled. The most common causes of an itchy scalp are harsh soaps and shampoos that remove oils and water from the scalp; hot showers or baths; chlorinated pools; air conditioning and heating that take moisture out of the air; and winter weather with low humidity.
Psoriasis
The University of Maryland Medical Center states that psoriasis is a common cause of itchiness in people from the ages of 15 to 35. It can affect areas all over the body including the scalp. Psoriasis tends to flare up and then disappear. It is thought to be an inherited immune disorder in which the body mistakes healthy cells for invading substances. Triggers appear to be too much sunlight or alcohol; too little sunlight; bacterial or viral infection; beta-blockers, anti-malaria drugs, and lithium medications; injured skin and stress.
Dandruff
Dandruff is characterized by flaking and itching of the scalp. Not contagious, most case are mild and respond to a daily cleansing with a mild shampoo. For more serious cases a medicated shampoo usually is effective. MayoClinic.com states the causes as lack of regular cleansing; eczema; contact dermatitis, or sensitivity to shampoos, conditioners or other hair care products; and malassezia, a fungus that normally lives on scalps but may grow out of control.
Seborrheic Dermatitis
Seborrheic dermatitis is characterized by inflammation of the top skin layers. The scalp becomes red and itchy, sheds dry or greasy scales and, in adults, is recurring. In infants, this condition is better know as "cradle cap." The cause of seborrheic dermatitis is hereditary and may be exacerbated by cold weather.
